Casting mold



Patented Mar. 9, 1926.

UNITED STATES ADOLF LEINWEBEB, 0F MUNICH, GrIillEtMANY.l

CASTING MOLD.

Application filed August 9, 1924. Serial No. 731,228.

To all whom, it may concern:

Be it known that I, ADoLF LEINWEBER, citizen of Germany, residing at Munich, Bavaria, Germany, have invented certain new and useful Improvements in Casting Molds (for which l filed an application in Germany, April 13, 1923) and l do hereby declare the following to bea full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains t0 make and use the same.

My invention relates to improvements in casting-molds and it refers more particularly to that class of casting molds used in the making of printing-plates for rotary presses. The object of my invention is to provide a mold of this character in which certain disadvantages, present in existing molds, are done away with.

The invention is illustratively exemplified in the' accompanying drawing in which Figuse 1 is a partial vertical section through the ingate-end of a mold and Figure 2 is a -partial longitudinal section through the said mold-portion.

In the casting of plates for rotary printing presses where the mold was not attached to the kettle, it was customary heretofore with the object of obtaining a uniformly solid and homogeneous printing-plate with a smooth, well cast face, to pour into the ingate of the mold a considerably larger quan.- tity of the molten metal than was actually required, to produce the plate thereby producing a dead-head, which was used to press upon the molten metal by the action of its own weight and into the face ofthe matrix and also furnish complementary molten metal required by the reduction of the volume of the molten metal when the printingplate coagulates. f f

rlhe dead-head requires the same quantity of molten metal as the printing-plate itself and as it must be detached and remelted, there is a waste of fuel which is just as large as the Aquantity required for the printingplate alone. The detaching of the dead-head from the congealed plate in most cases also requires a special det-achingor other machine-tool. According to my invention l obviate the defects of existin casting molds or boxes by dispensing with t e so-called dead-head and using in lieu thereof a .pressure plate, which is desirably made of sections each of which is capable of acting independently of the others, designed to press upon the upper surface of the molten metal in the mold.

As shown in Figure 2 l provide a pressureplate a contiguous to and preferably behind the gate-hole which plate is vertically reciprocable so 'as to' exert upon the molten metal that pressure which was heretofore exertled by the dead head in the casting-funne c.

The mold may be-lled in the saine way as heretofore and then the pressure-plate a should. be lowered to the place indicated by the dotted line b, so that it will press on the molten metal which is now prevented from escaping.

As the surface upon which the pressureplate acts does not congeal at the same time throughout its entire length and as no new molten metal can flow thereto, as was the case, when the dead-head and the printingplate Would congeal all at the same time, it is not impossible that the part of the printing-plate which first congeals might lack homogeneity and be porous and thus cause flaws or gaps in the face.

ln order to prevent thisl prefer to form the said pressure-plate of a plurality of parts, as shown in Figures 1 and 2, each part yacting forl itself i. e. independently of the. other parts on the surface to be pressed. The portion of that surfacewhich cools down last, will then be still under pressure which cannot be exerted, however, by the other plates,`

because beneath them the metal has already become solid. As by this time the last portion of the printing-platev has also solidified, the whole plate will' be of uniform consistency. As circumstances may require, the pressureplate may be made up of a .nnaller or larger number of these plate-members.

` rlihe pressure may be effected by springaction, or by weight or by lever-action or by Ameans of any mechanical device which forms no part of my invention and does not require to be illustrated. The molten metal present in the funnel serving to heat the pressure-plates, remaining after the descent of the latter is returned in a fluid state, to the kettle. The making of the printing-plates is a simple operation. l close the mold by means of the core o. rlhe metal may be introduced by means of a ladle or a pump or direct from the pit. l then operate the pressure-plates and thereupon discharge either by hand or automatically the molten matter in the funnel c. After theprinting-- plate has become cool I lift the core o with the printing-plate from the basin n.

The saving of dead-head attained in this Way has the advantage that With the same quantity of molten feed there may be made a double number of printing-plates, or in case such a larger number is not required, the saine number of plates may be made' with a foundry-furnace which is half as small as one which would be required if dead-head were employed. The fact that the meltingpan of this Smaller furnace has a thinner wall and bottom and will therefore be heated much more rapidly, the smaller quantity of metal will be brought to the required castingtemperature Within a shorter time and the saving of fuel, as compared with former methods, will amount to at least one half. Another, still greater advantage is that it is no longer necessary to remove the dead-head I machine.

I claim 1. In a mold for casting printing plates for rotary printing presses, the combination With the ingate funnel in said mold, of a reciprocable pressure plate movable in a path in said mold adjacent to said funnel.v p

2. In a mold for casting printing plates for rotary printing presses, the combination with' the ingate funnel in said mold, of a reciprocable ressure plate movable in a path in the mold) adjacent said funnel, said pressure plate comprising a plurality of independently movable sections.

3. A mold of the character described having an ingate funnel and an adjacent guide passage thereinhand a pressure plate reciprocable 1n said gulde passage.

In testimony whereof I hereunto aflix my signature.

ADOLF LEINWEBER. 

